The Roberts Sand Company Black Diamond is a silica mine located in Contra Costa county, California.
About the MRDS Data:
All mine locations were obtained from the USGS Mineral Resources Data System. The locations and other information in this database have not been verified for accuracy. It should be assumed that all mines are on private property.
Primary Mineral: Silica
Lat, Long: 37.9575, -121.88306
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Roberts Sand Company Black Diamond MRDS details
Site NamePrimary: Roberts Sand Company Black Diamond
County: Contra Costa
Years: 1957 -
Operation Category: Producer
Operation Type: Unknown
Years of Production:
PhysiographyGeneral Physiographic Area: Pacific Mountain System
Physiographic Province: Pacific Border Province
Physiographic Section: California Coast Ranges
Mineral Deposit Model
|Comment: MINED AND PROCESSED SAND OVER A PERIOD OF NEARLY 25 YEARS, DURING WHICH TIME TOTAL PRODUCTION AMOUNTED TO 367,543 TONS OF SAND VALUED AT $1,347,630. WORKED FOR SAND 1925--49 BY COLUMBIA STEEL CO., ROBERTS ET AL; REOPENED BY SILVER SAND CO. IN 1957. OPERATIONS AT THIS PROPERTY WERE SUSPENDED IN NOVEMBER 1949.|
|Comment: ROOM AND PILLAR METHOD UTILIZING HAND AUGER DRILLS.|
Reference Category: Deposit
Reference: CALIF. JOUR. VOL. 47, NO. 4, OCT. 1951, PP. 583-4; V. 54, NO. 4, OCT. 1958, P. 554, 555, 580, PL.